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A high 5-HMF yield of 85.4% was achieved in polar aprotic oxygen-containing solvent with strong electrophilic maleic acid by quenching DHH.

Herein, we report a highly efficient non-noble bimetallic Ni–Mn/SiO2 catalyst for the selective hydrogenation of biomass-derived levulinic acid to γ-valerolactone under mild reaction conditions.

Lithium-Sulfur (Li-S) batteries with high theoretical energy density are promising energy storage systems in the next decades, while the lithium polysulfides (LiPSs) shuttling caused by the sluggish sulfur redox reaction severely lowers the practical performance. The use of interlayer between the cathode and separator has been widely investigated to physically or chemically block the LiPSs, while the introduction of catalytic materials is a more effective strategy to accelerate the conversion of LiPSs. MXene with rich surface chemistry has shown its potential for facilitating the catalytic conversion, however, the aggregation of MXene sheets usually leads to the loss of the catalytic active sites. Herein, we report a diatomite/MXene (DE/MX) hybrid material as the bifunctional interlayer for improving the adsorption/conversion of LiPSs in Li-S batteries. The diatomite with porous structure and rich silica-hydroxyl functional groups could trap LiPSs effectively, while prevent the aggregation of MXene. The DE/MX based interlayer showed bifunctions of enhancing the chemical adsorption and promoting the conversion of LiPSs. The Li-S batteries with the DE/MX interlayer delivered an improved cycling stability with a low capacity decay of 0.059% per cycle over 1000 cycles at 1.0 C. Moreover, stable 200 cycles can be realized with a high sulfur loading electrode up to 6.0 mg cm−2. This work provides an effective strategy to construct bifunctional interlayers for hindering the shuttling of LiPSs and boosting the practical application of Li-S batteries.

The selective reductive amination of levulinic acid (LA) into pyrrolidone derivatives is regarded as one of the most promising reactions in the fields of biomass conversion into high value-added chemicals. Herein, we report a one-pot synthesis of N-substituted-5-methyl-2-pyrrolidones by reductive amination of LA/ester with nitriles over several commercial catalysts. Among the catalysts texted, Pd/C was found to be the most efficient for the reductive amination of LA/ester with various nitriles to give high yields of pyrrolidones (up to 92%) under mild reaction conditions (80 °C, 1.6 MPa H2, tetrahydrofuran solvent). And the catalyst showed good reusability.

Designing highly efficient and low-cost catalysts for conversion of renewable biomass into high value-added chemicals and biofuels is important and challenging. Herein, a non-noble Ni-Mn bifunctional catalyst supported on activated carbon (Ni-Mn/AC) was developed by an incipient wetness impregnation method. The catalyst was found to be economic and efficient for the selective hydrodeoxygenation of biomass-derived 5-hydroxymethylfurfural (5-HMF) to 2,5-dimethylfuran (2,5-DMF). The optimal Ni-Mn/AC (Ni/Mn=3) catalyst achieved 98.5 % 2,5-DMF yield with 100 % conversion of 5-HMF under mild reaction conditions of 180 °C, 2.0 MPa H

Supported Co/activated carbon (Co/AC) catalysts were prepared by the incipient wetness impregnation method and applied to the one-pot hydroamination of isophorone nitrile (IPN) into isophorone diamine (IPDA). The 20 wt% Co/AC heat-treated in N2 exhibited superior catalytic performance to the 20 wt% Co/AC heat-treated in H2, by which a maximum 90.2% yield of IPDA was achieved and it could be recycled at least four times. XRD, XPS, TEM and BET has demonstrated that the existence of the fcc form of Co as well as the smaller and more uniformly dispersed Co particles in the Co/AC catalyst heat-treated in N2 may contribute to the excellent catalytic performance.

In the present work, a series of Pt-based catalysts, alloyed with a second metal, i.e., Re, Sn, Er, La, and Y, and supported on activated carbon, ordered mesoporous carbon, N-doped mesoporous carbon or reduced graphene oxide (rGO), have been developed for selective hydrogenation of cinnamaldehyde to cinnamylalcohol. Re and rGO were proved to be the most favorable metal dopant and catalyst support, respectively. Pt50Re50/rGO showed the highest cinnamylalcohol selectivity of 89% with 94% conversion of cinnamaldehyde at the reaction conditions of 120 °C, 2.0 MPa H2 and 4 h.

Herein, Cu(NO3)2/acetonitrile was proven to be an efficient oxidation system in the oxidation of 5-HMF to DFF in an aqueous solution. After optimization of the reaction conditions, the DFF yield of 97.0% was obtained under the conditions of 1.5 mmol 5-HMF, 1.5 mmol Cu(NO3)2, 0.48 ml acetonitrile, 10 ml H2O, 80 °C, and 18 h. The oxidation system could be recycled at least three times by adding HNO3, which avoided the risk of production of Cu-containing waste. The formation of Cu(CH3CN)4+ in the aqueous solution played an important role in enabling the oxidation of 5-HMF via the redox cycle of Cu2+/Cu+. To further improve the reaction efficiency, a reactive-extraction process was developed by introducing toluene as the organic phase due to its excellent extraction capacity for DFF. As a result, the reaction time was shortened to 8 h, and the highest DFF yield of 98.9% was achieved.

In our previous work, graphene-supported Pd catalyst (Pd/rGO) exhibited higher activity and selectivity for the liquid phase selective hydrogenation of resorcinol to 1,3-cyclohexanedione compared with other catalysts. In the present study, further experimental and theoretical investigations were conducted to reveal the reaction mechanism and the catalytic mechanism of Pd/rGO for resorcinol hydrogenation. The effects of graphene nanosheet and the solvent on the reaction were investigated, and the pathway for resorcinol hydrogenation was proposed supported by density functional theory (DFT) calculations. The results showed that the excellent selectivity of Pd/rGO to 1,3-cyclohexanedione was attributed to the strong π–π and p–π interactions between the graphene nanosheet and the benzene ring as well as hydroxyl in resorcinol molecule, which was in agreement with our previous speculation. In weak polar aprotic solvents, solvation free energy had less impact to the π–π and p–π interactions mentioned above. In strong polar aprotic solvents and polar protic solvents, however, the influence of solvation free energy was much greater, which led to the decrease in the conversion of resorcinol and the selectivity to 1,3-cyclohexanedione.

Hydrogenation of levulinic acid to γ-valerolactone is a key reaction in the valorization of carbohydrates to renewable fuels and chemicals. State-of-the-art catalysts are based on supported noble metal nanoparticle catalysts. We report the utility of a bimetallic Fe-Re supported on TiO2 for this reaction. A strong synergy was observed between Fe and Re for the hydrogenation of levulinic acid in water under mild conditions. Fe-Re/TiO2 shows superior catalytic performance compared to monometallic Fe and Re catalysts at similar metal content. The hydrogenation activity of the bimetallic catalysts increased with Re content. H2-TPR, XPS, XANES, EXAFS, Mössbauer spectroscopy, TEM, and low-temperature CO IR spectroscopy show that the bimetallic catalysts contain metallic Re nanoparticles covered by FeOx species and small amounts of a Fe-Re alloy. Under reaction conditions, the partially reduced surface FeOx species adsorb water and form Brønsted acidic OH groups, which are involved in dehydration of reaction intermediates. Under optimized conditions, nearly full conversion of levulinic acid with a 95 % yield of γ-valerolactone could be achieved at a temperature as low as 180 °C in water at a H2 pressure of 40 bar.

The effects of the surfactant hexadecyltrimethylammonium bromide (CTAB) on the catalytic performance of a manganese-promoted iron (FeMn) catalyst for the Fischer–Tropsch to olefin (FTO) reaction were investigated. The use of the CTAB-assisted FeMn catalyst resulted in the production of light olefin (C2–4) selectivity of up to 55.45% with a ratio of olefin to paraffin among the C2–C4 hydrocarbons as high as 7.75 under industrially relevant conditions (320 °C, 1.0 MPa, H2/CO ratio of 1.5 (v/v), GHSV = 4200 h−1). The characterization results indicate that CTAB has a great influence on the structure, composition, chemical state, and catalytic performance of the iron-based catalyst. Most interestingly, a greater amount of Mn promoter was found to be dispersed on the surface of α-Fe2O3, rather than being dissolved into the α-Fe2O3 lattice when CTAB was employed, which contributed towards enhancing the promotional effects of the Mn promoter, leading to the formation of certain surface-specific activity sites.

Mesoporous carbon (MC) and nitrogen-doped mesoporous carbon (NMC) were prepared through a dual-template approach with tetraethyl orthosilicate and Pluronic F127 as a dual-template, and phenol-formaldehyde and melamine-phenol-formaldehyde resins as carbon and carbon + nitrogen sources, respectively. Using them as the supports, the Pt/MC and Pt/NMC catalysts were prepared by incipient wetness impregnation method and used for the decarboxylation of saturated and unsaturated fatty acids to alkanes. Activated carbon supported Pt catalyst (Pt/AC) was also prepared for comparison. Among the three catalysts, Pt/NMC exhibited the highest catalytic performance, achieving yields of the corresponding alkanes of more than 97.0% from lauric, myristic, palmitic and stearic saturated acids and 44.0%–66.1% from oleic and linoleic unsaturated fatty acids. The turnover frequencies of Pt/NMC were estimated as 335–522 h−1 in the decarboxylation of saturated acids, which were almost 2-fold higher than Pt/MC and 3-fold higher than Pt/AC. The excellent performance of the Pt/NMC catalyst might be attributed to the introduction of N species to the MC support, which not only improved the anchoring and the dispersion of Pt nanoparticles on the catalyst surface, but also provided alkaline sites to adsorb carboxyl group in fatty acids.

A series of PdNi/SiO 2 bimetallic nanoparticles were synthesized using polyvinylpyrrolidone (PVP) and 2,6-bis(5,6-dimethyl-1,2,4-triazine-3-yl) pyridine (BTP) as ligands through sol-gel method. BTP was proved to be an effective ligand that can delay the reduction of palladium (II), which helps the formation of palladium-rich shell bimetallic nanoparticles. Pd 3 Ni 7 -BTP/SiO 2 exhibited the best catalytic performance (TOF = 180 h − 1 ) among all the catalysts for hydrogenation of nitrobenzene under ambient conditions and was successfully reused for at least five times without loss in activity. The excellent catalytic performance could be ascribed to the small nanoparticle size (2.14 nm) and the palladium-rich shell structure it bears.

RANEY® Ni proved to be an effective heterogeneous catalyst for switchable reductive amination of furfuryl alcohol to tetrahydrofurfurylamine and furfurylamine with NH3 by simply adding or not adding 1.0 MPa H2 into the reaction bulk. After further optimization of the reaction conditions, we finally obtained 94.0% yield of tetrahydrofurfurylamine and 78.8% yield of furfurylamine with high selectivity. By extensively studying the catalytic pathways and mechanism of catalyst deactivation with XRD and XPS characterization, we have confirmed that an excess amount of H2 in the reaction bulk leads to the deep hydrogenation of the furan ring while an insufficient amount of H2 leads to the formation of Ni3N and the deactivation of the catalyst.

Different iron carbides were synthesized from the iron oxalate precursor by varying the CO carburization temperature between 320 and 450 &deg, C. These iron carbides were applied to the high-temperature Fischer&ndash, Tropsch synthesis (FTS) without in situ activation treatment directly. The iron oxalate as a precursor was prepared using a solid-state reaction treatment at room temperature. Pure Fe5C2 was formed at a carburization temperature of 320 C, whereas pure Fe3C was formed at 450 &deg, C. Interestingly, at intermediate carburization temperatures (350&ndash, 375 &deg, C), these two phases coexisted at the same time although in different proportions, and 360 &deg, C was the transition temperature at which the iron carbide phase transformed from the Fe5C2 phase to the Fe3C phase. The results showed that CO conversions and products selectivity were affected by both the iron carbide phases and the surface carbon layer. CO conversion was higher (75&ndash, 96%) when Fe5C2 was the dominant iron carbide. The selectivity to C5+ products was higher when Fe3C was alone, while the light olefins selectivity was higher when the two components (Fe5C2 and Fe3C phases) co-existed, but the quantity of Fe3C was small.

Graphene is a hot topic in many research fields due to its outstanding physicochemical properties. It is also a new carbon catalyst support after activated carbon, carbon nanotube, fullerene and mesoporous carbon. In the present article, we focused on the application of graphene in the field of catalytic hydrogenation, summarized the preparation and characterization of graphene, and discussed the advantages and disadvantages of graphene as a catalyst support and metal-free catalyst. Some factors that may affect the catalytic hydrogenation activity have also been discussed in detail.

An efficient catalysis system composed of a Lewis–Bronsted acid mixture and Ru/C using N,N-dimethylformamide as a solvent was developed for the one-pot conversion of fructose to 2,5-dimethylfuran (2,5-DMF) via the dehydration/hydrogenolysis sequence. The effects of various reaction parameters, such as solvent, catalyst type, catalyst loading, reaction pressure, temperature and time, on single fructose dehydration, 5-hydroxymethylfurfural (5-HMF) hydrogenolysis and the one-pot conversion of fructose to 2,5-DMF were systematically investigated. The results showed that 2,5-DMF could be successfully produced with a yield as high as 66.3 mol% by using a one-pot method directly from fructose under the optimized reaction conditions, which is by far the highest yield ever reported for the production of 2,5-DMF from fructose through a one-pot strategy. The Ru/C catalyst could be reused at least three times with a slight decrease in 2,5-DMF yield.

The catalytic reactivity of synthetic bare magnetite nanoparticles, activated carbon supported magnetite (AC-Mt), and graphene oxide supported magnetite (GO-Mt) for heterogeneous Fenton-like oxidation of methylene blue (MB) were compared, in order to investigate how the structural features of the support impact catalytic activity of the nanocomposites. The different effects of AC and GO on MB removal rate, hydroxyl radical (˙OH) production, iron leaching, and surface deactivation have been systematically studied. The rate constant of MB removal by AC-Mt was 0.1161 min−1, one order of magnitude larger than the value of bare magnetite nanoparticles (0.0566 min−1). The higher catalytic activity of AC-Mt might be attributed to the larger reactive surface area of well-dispersed magnetite for ˙OH production and the recharge of the magnetite surface by the AC support via Fe–O–C bonds. However, the removal rate of MB by GO-Mt was one order of magnitude slower than that of bare magnetite nanoparticles under the same experimental conditions, presumably due to the wrapping of GO around magnetite nanoparticles or extensive aggregation of GO-Mt composites. These findings revealed the significant influence of support structure on the catalytic activity of carbon-supported magnetite nanocomposites, which is important for the development of efficient magnetite-based catalysts for wastewater treatments.

A series of cobalt-based catalysts supported on several acidic/basic oxides were prepared by the incipient wetness impregnation method and applied for the one-pot synthesis of isophorone diamine (IPDA) from hydroamination of isophorone nitrile (IPN). The effects of the supports and cobalt loading on the performance of the catalysts were investigated. The results showed that the Co/SiO2 catalyst with 20 wt % Co loading gave the highest conversion of IPN (90.9%) and yield of IPDA (70.4 mol %) among the supported cobalt catalysts used in this work, and it could be reused eight times without a significant decrease in the catalytic performance, which was much better than that from the commercial Raney Co. Meanwhile, the possible intermediates and reaction pathways during hydroamination of IPN were provided.

Activated carbon supported nickel-based catalysts doped with Fe were prepared by the incipient wetness impregnation method. In order to improve the acid-resistant stability of the catalyst, the nickel catalysts supported on hydrophobic activated carbon were also prepared by the same method. The as-prepared catalysts were applied for the liquid phase selective hydrogenation of phthalic anhydride to phthalide. The experimental results showed that Fe doped Ni/activated carbon catalyst containing 5 wt.% Fe and 15 wt.% Ni had the best catalytic performance among the nickel catalysts tested, with 100% of phthalic anhydride conversion and 95.2% of selectivity to phthalide at 180 °C and 4.0 MPa H2. When the activated carbon support was pretreated with NaBH4, the acid-resistant ability of the as-prepared Ni–Fe catalyst was remarkably enhanced, and the catalyst could be reused more than 8 times with slight decrease in activity, which was much better than the one without hydrophobization. The remarkable catalytic performance might be attributed to (1) the addition of Fe to form an alloy with Ni, dispersing the electron clouds around Ni atoms and stabilizing the Ni catalyst; (2) the application of hydrophobilized activated carbon as a support, preventing produced water from contacting the metal surface, which could reduce the corrosion of Ni as the activity of the H+ concentration decreases.

A highly efficient and reusable catalyst, palladium (II) complex supported on functionalized silica, was prepared by anchoring palladium (II) onto 2,6-bis(5,6-dimethyl-1,2,4-triazine-3-yl)pyridine [BTP]-modified mesoporous silica (labeled as Pd-BTP/SiO2). The catalyst was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and Brunauer Emmett Teller (BET) analysis. Its catalytic performance was tested for the Heck coupling reactions between aryl halides with acrylic acid or styrene, and good to excellent results (higher conversions 87–96% and yields 66–78%) were obtained. The catalyst system was stable under the reaction conditions and could be successfully reused more than five times without the loss of catalytic activity.

Gold catalysts supported on FeO x –TiO 2 with various Fe 2 O 3 contents were prepared by deposition–precipitation method and used for phthalic anhydride hydrogenation to phthalide. The effect of Fe 2 O 3 on the physico-chemical property and the performance of Au/TiO 2 were investigated. The reaction conditions were optimized. Adding 5 wt.% Fe 2 O 3 on Au/TiO 2 could enhance the activity and stability, which was contributed to the increase in the strength of the catalyst structure and the decrease in the loss of gold from catalyst. Using Au/5%FeO x –TiO 2 , phthalic anhydride conversion and phthalide selectivity reached 95.4% and 94.5%, respectively, at 190 °C and 3.0 MPa H 2 for 7 h.

The reaction process and kinetics of the selective hydrogenation of resorcinol to 1,3-cyclohexanedione on Pd/C were studied. The optimized reaction conditions were as follows: mole ratio of sodium hydroxide to resorcinol, 1.1–1.2; catalyst loading, 15% ( w / w ); hydrogen pressure, 2 MPa; reaction temperature, 353 K; and stirring speed, >800 rpm. A kinetic model was then established based on a report that two hydrogenation pathways simultaneously control hydrogenation: one is the simultaneous addition of two hydrogen atoms while a van der Waals complex forms between the aromatic π-bond and the catalyst surface; the other is the sequential addition of a single hydrogen atom while a π/σ complex forms between a single double-bond and the catalyst surface. Subsequently, the model parameters and activation parameters were estimated. Results showed that the reaction was mainly controlled by the sequential pathway and that the addition of the first hydrogen atom was the rate-determining step. The activation energies for the sequential addition of two hydrogen atoms were 19.9 and 35.0 kJ / mol, whereas the activation energy for the simultaneous addition of two hydrogen atoms was 54.1 kJ / mol. The adsorption heats for resorcinol and 1,3-cyclohexanedione on the catalyst surface were 63.4 and 25.7 kJ / mol, respectively.

Solid acid catalysts of graphene oxide and sulfonated graphene oxide nanosheets have been prepared by using the modified Hummers and sulfonation methods. Physical characterization indicated that a number of functional groups such as COOH, OH, O, and SO3H were introduced onto the surfaces of the as-synthesized nanosheets. The catalytic performance of the synthesized catalysts was evaluated in the hydrolysis of the glycosidic bond and Fischer esterification. The experimental results indicated that the catalytic activity of the sulfonated graphene oxide was superior to that of other solid acid catalysts with the same or higher acid strength and has also exceeded that of H2SO4 with 9.1 times of acid strength than that of the sulfonated graphene oxide. The high reactivity can be ascribed to the formation of hydrophobic cavities through the combination of graphene sheet and the oxygen-containing groups on its surface, which may facilitate the catalyst to anchor with reactants and promote the attack of protons.

We have developed an effective route for obtaining 5-hydroxymethylfurfural with a yield of 92.6 mol% from the dehydration of fructose in N,N-dimethylformamide using a mixture of AlCl3, H2SO4 and H3PO4 as catalyst. The NMR analysis showed the intermediate formed among fructose, AlCl3 and H3PO4 plays an important role in the novel result.

To achieve a higher activity and reusability of a Ru-based catalyst, Ru nanoparticles were embedded in N-doped mesoporous carbon through a hard-template method. The catalyst showed excellent catalytic performance (314 h−1 turnover frequency) and recyclability (reusable five times with 3 % activity loss) for the hydrogenolysis of levulinic acid to γ-valerolactone. Compared with the mesoporous carbon without N-doping and conventional activated carbon, the introduction of N-dopant effectively improved the dispersion of Ru nanoparticles, decreased the average size of Ru nanoparticles to as small as 1.32 nm, and improved the adsorption of levulinic acid, which contributed to the increase in the activity of the catalyst. Additionally, the embedding method increased the interaction between Ru nanoparticles and carbon support in contrast with the conventional impregnation method, thus preventing the Ru nanoparticles from migration, aggregation, and leaching from the carbon surface and therefore increasing the reusability of the catalyst.

Liquid phase hydrogenation of nitrobenzene to p-aminophenol (PAP) in water was studied over a catalyst system composed of Pt/C and carbon-based solid acid which was prepared by one-step hydrothermal carbonization of various carbon sources including starch, sucrose, glucose and furfural in sulfuric acid aqueous solution at 180 °C for 4 h. The effects of carbon-based solid acid type, Pt/C catalyst loading, hydrogen pressure and reaction temperature on nitrobenzene conversion and PAP selectivity were investigated. The results showed that PAP selectivity was favored at high acid density of the carbon-based solid acid. The carbon-based solid acid prepared from starch, with the highest SO3H amount, gave the highest PAP selectivity among the catalysts used. An increase in Pt/C catalyst loading led to an increased nitrobenzene conversion but a decreased PAP selectivity. A high reaction temperature was in favor of nitrobenzene conversion and PAP selectivity. Under the optimal reaction conditions, nitrobenzene conversion and PAP selectivity reached 61.0% and 77.8%, respectively.

2-Methyl-4-methoxyaniline (MMA) was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o -nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The effects of ionic liquid type, dosage of ionic liquid and 3% Pt/C, reaction temperature and reaction pressure on o -nitrotoluene conversion and MMA selectivity were investigated. The results indicated that the imidazolium-based acidic ionic liquid which contains SO 3 H-functionalized cation showed higher selectivity to MMA than other acidic ionic liquids used in this work. Using 1-(propyl-3-sulfonate)-3-methylimidazolium hydrosulfate ([HSO 3 -pmim][HSO 4 ]) as the acid catalyst, the selectivity to MMA was as high as 67.6% at 97.8% of o -nitrotoluene conversion. As 3% Pt/C increased from 0.01 g to 0.025 g, the selectivity to MMA decreased from 73.4% to 62.5%, because of the hydrogenation of intermediate o -methyl-phenylhydroxylamine to o -toluidine becoming more dominant. An increase in hydrogen pressure also had obviously dramatic effect in lowering the MMA selectivity. After easy separation from the products, the catalyst system could be reused at least 3 times.

Catalytic dehydration of carbohydrates into 5-hydroxymethylfurfural (5-HMF) has been studied in the presence of ionic liquids, i.e., 1-butyl-3-methyl imidazolium chloride ([BMIM]Cl) and triethylamine sulphate ([Et3NH][HSO4]) using metal salts as catalysts. Novel metal chlorides IrCl3 and AuCl3·HCl as catalysts in ionic liquid showed remarkable activity and selectivity to 5-HMF for the reaction of fructose dehydration. The reaction conditions of fructose dehydration were optimized as follows: reaction temperature 120 °C, reaction time 30 min, IrCl3 content 7% (mol% based on fructose) in [BMIM]Cl, at which the conversion of fructose and the yield of 5-HMF reached 97.7% and 89.0%, respectively. By simply assuming the fructose simultaneously converts to 5-HMF and other by-products by the first-order reaction kinetics, the energies of activation are estimated to be 165 kJ/mol for the formation of 5-HMF and 124 kJ/mol for the formation of other by-products from 80 to 100 °C, respectively. The existence of water in the media more than 0.5% (v/v) would significantly slow down the dehydration rate of fructose, while it seemed not necessary to further remove water during the reaction when the water was less than 0.5%. Compared with the dehydration of fructose, the dehydration of other carbohydrates such as glucose, sucrose and maltose was rather difficult.

BACKGROUND: Liquid-phase catalytic hydrogenation of m-dinitrobenzene is an environmentally friendly routine for m-phenylenediamine production. The key to increasing product yield is to develop catalysts with high catalytic performance. In this work, La 2 O 3 -modified Ni/SiO 2 catalysts were prepared and applied to the hydrogenation of m-dinitrobenzene to m-phenylenediamine. The effect of La 2 O 3 loading on the properties of Ni/SiO 2 was investigated. The reaction kinetic study was performed in ethanol over Ni/3%La 2 O 3 -SiO 2 catalyst, in order to clarify the reaction mechanism of m-dinitrobenzene hydrogenation. RESULTS: It was found that the activity of the silica supported nickel catalysts is obviously influenced by La 2 O 3 loading. Ni/3%La 2 O 3 -SiO 2 catalyst exhibits high activity owing to its well dispersed nickel species, with conversion of m-dinitrobenzene and yield of m-phenylenediamine up to 97.1 % and 94%, respectively. The results also show that Ni/3%La 2 O 3 -SiO 2 catalyst can be reused at least six times without significant loss of activity. CONCLUSION: La 2 O 3 shows strong promotion of the effect of Ni/SiO 2 catalyst for liquid-phase hydrogenation of m-dinitrobenzene. La 2 O 3 loading can affect the properties of Ni/SiO 2 catalyst. Based on the study of m-dinitrobenzene hydrogenation kinetics over Ni/3%La 2 O 3 -SiO 2 catalyst, a possible reaction mechanism is proposed.

Au/TiO 2 catalysts with different gold loadings were prepared by deposition–precipitation method and used for the liquid phase hydrogenation of phthalic anhydride. All the studied Au/TiO 2 catalysts exhibited excellent activity with high selectivity (>92%) to phthalide under mild reaction conditions (180 °C and 3.0 MPa H 2 ). Specially, catalysts with 2–3 wt.% gold loading were highly active and selective for the formation of phthalide. When reused, the catalyst showed a certain deactivation, but still was highly selective to phthalide. The deactivation was attributed to the leaching of gold, collapse of the pore structure and accumulation of organic species on the surface.

Alcoholysis of soybean isoflavone glucosides by butanol catalyzed by acidic ionic liquids was studied. The effects of the ionic liquid catalyst type, catalyst concentration, reaction time and reaction temperature on glycoside conversions, and aglycons yields were investigated. The optimum reaction conditions are found to be as follows: 0.036 g mL−1 of ionic liquid [BIM]HSO4 as catalyst, reaction temperature at 104±1°C, reaction time of 100 min. Under these optimum reaction conditions near complete conversions of the three kinds of glycosides (daidzin, glycitin and genistin) are obtained. Furthermore, the kinetics parameters for the alcoholysis were estimated. The activation energies of alcoholysis for the three kinds of isoflavone glucosides are 124 kJ mol−1, 67 kJ mol−1 and 115 kJ mol−1, respectively.

Ni-La2O3-SiO2 catalysts were prepared by wetness impregnation and sol-gel method followed by conventional drying and supercritical drying, respectively. Their physico-chemical properties and activity for the hydrogenation of m-dinitrobenzene to m-phenylenediamine were investigated by BET, XRD, TPR, H2-TPD and activity tests. The results showed that the structural and catalytic properties of the Ni-La2O3-SiO2 catalysts obviously depended on the preparation method and the drying mode. The catalyst prepared by the sol-gel method in combination with conventional drying exhibited the highest catalytic activity among the catalysts tested, attributable to its well-dispersed nickel particles and larger active nickel surface area.

The selective hydrogenation of resorcinol (RES) to 1, 3-cyclohexanedione (1,3-CHD) without the addition of alkali is a big challenge. In this article, a novel reduced graphene oxide (rGO) supported Pd catalyst was prepared through co-reduction method, over which we obtained 99.9% of resorcinol conversion and 94.2% of the ever-reported highest 1,3-cyclohexanedione selectivity at 25 °C in only CH2Cl2 solvent. The excellent selectivity was contributed to the strong π-π and p-π interactions between the graphene nanosheet and the benzene ring as well as hydroxyl in RES molecule. The followed adsorption experiment and Raman analysis also showed the existence of aromatic graphite structures in rGO, which exhibited stronger adsorption towards RES than towards 1,3-CHD.

The liquid-phase hydrogenation of m-dinitrobenzene to m-phenylenediamine was studied over silica-supported nickel catalyst. The effects of Ni loading, calcination temperature, and reduction temperature on the physicochemical characteristics and activity of the catalyst were investigated by XRD, TEM, TPR, and activity tests. The results show that the silica-supported nickel catalysts exhibited high catalytic property, which depended on the particle size of Ni and the reduction degree of NiO. The optimal Ni loading, calcination temperature and reduction temperature of the catalyst for m-dinitrobenzene hydrogenation were found to be 20 wt%, 773 K in air and 723 K, respectively. Under this condition, 97.2% conversion of m-dinitrobenzene and 88.9% yield of m-phenylenediamine were obtained at 373 K and 2.6 MPa hydrogen pressure. The particle size of nickel species increased with the increase in Ni loading or calcination temperature. In addition, it was found that the catalyst could not be completely reduced at low reduction temperature, whereas high reduction temperature led to the sintering of Ni.

As more and more novel catalyst systems are being developed for the dehydration of carbohydrates, especially glucose, an effective way to separate the dehydration product 5-hydroxylmethylfurfural (5-HMF) is also required for industrial manufacturing. In this paper, for the first time, we have developed a process called EIVRD (entrainer-intensified vacuum reactive distillation) to separate 5-HMF from the dehydration solutions of carbohydrates catalyzed by a metal chloride/1-methyl-3-octyl imidazolium chloride ([OMIM]Cl) ionic liquid, in which high vacuity and entrainers were applied to intensify the distillation of 5-HMF as well as the dehydration of fructose or glucose. In such an EIVRD process, the average recoveries of 5-HMF dehydrated from fructose and glucose are around 93% and 88%, respectively. The recycling of the catalyst system in the EIVRD process is so convenient that the recovery and actual yield of 5-HMF is successfully repeated during the whole five recycled reactions.